Electric detonator system for projectiles

ABSTRACT

An electric detonator system is disclosed which includes a primer-oscillating slide for closing one portion of a detonator circuit, and an impact switch for closing another portion of the detonator circuit. The slide is shiftable from a safety position to a primed (circuit-closing) position. The impact switch is shiftable from a circuit-open position to a circuit-closed position in response to impact of an associated projectile. The slide, when in its safety position, is operable to lock the impact switch in the latter&#39;&#39;s circuit-open position. Upon being shifted to its primed position, the slide permits movement of the impact switch to the latter&#39;&#39;s circuit-closed position. The various elements of the detonator system are compactly arranged to define a structure which may be conveniently inserted as a unit within a detonator housing.

United States Patent [1 1 Kaiser Nov. 5, 1974 1 ELECTRIC DETONATOR SYSTEM FOR PROJECTILES [75] lnventor: Hans Kaiser, Konigsfeld, Germany [73] Assigncc: Gebruder Junghans G.m.b.H., 723

Schramberg, Germany [22] Filed: Jan. 15, 1973 [2]] Appl. No.: 323,417

[30] Foreign Application Priority Data Jun. 24, 1972 Germany 2203216 [52] US. Cl. 102/70.2 R, 102/78 [51] Int. Cl...... F42c 11/00, F42c 15/24, F420 9/02 [58] Field of Search 102/70, 70.2, 78

[56] References Cited UNITED STATES PATENTS 2,748,704 6/1956 Dinsmoor l02/70.2 R 3,004,49l lO/l96l Pace et al. lO2/70.2 R 3.613589 l0/l97l Apstein et al 102/70.2 R 3,675,579 7/1972 Min l()2/70.2 R 3,720,165 3/1973 Dinsmoor l02/70.2 R

Primary Examiner-Benjamin A. Borchelt Assistant Examiner-Thomas l-l. Webb Attorney, Agent, or FirmBurns, Doane, Swecker & Mathis 5 7 ABSTRACT An electric detonator system is disclosed which includes a primer-oscillating slide for closing one portion of a detonator circuit, and an impact switch for closing another portion of the detonator circuit. The slide is shiftable from a safety position to a primed (circuit-closing) position. The impact switch is shiftable from a circuit-open position to a circuit-closed position in response to impact of an associated projectile. The slide, when in its safety position, is operable to lock the impact switch in the latters circuit-open position. Upon being shifted to its primed position, the

slide permits movement of the impact switch to the latters circuit-closed position.

The various elements of the detonator system are compactly arranged to define a structure which may be conveniently inserted as a unit within a detonator housing.

4 Claims, 7 Drawing Figures PMENIEDNBV 51914 3.845.714 sum as; 3

ELECTRIC DETONATOR SYSTEM FOR PROJECTILES BACKGROUND OF THE INVENTION The invention relates to an electric primer detonator for projectiles which includes an impact switch disposed in a detonator circuit, and a primer-oscillating slide containing a primer and an electric ignition element (developed as a safety switch), wherein the slide establishes an electric contact between the electric ignition element and the detonator circuit only in its primed position.

An electric impact detonator of the above-mentioned type has been known (see Austrian Pat. No. 224,512).

This detonator has an impact element disposed at the nose of the projectile and a rotor, lying behind the hollow charge, containing the electric detonating element. At the same time, two contacts are provided in the area of the rotor, which are connected with the detonating switch by insulated wires and with which the detonating element is connected by means of the rotor in its primed position. The mounting of this detonator is complicated because of the wires leading from the detonator switch to the rotor. Besides, the-individual construction units in the mounted detonator are not very accessible, as a result of which a functional test of the detonator after being mounted is made difficult. A further disadvantage of the known detonator is due to the fact that the impact switch, which is designed as a spring-mass-system, is not secured mechanically, so

that it is moved by any shocks that might occur, for example, during transportation, which can lead to an undesired detonation. Moreover, there is a danger of the impact switch being temporarily closed, in which case the detonating circuit is kept open only by the rotor. This does not correspond to present day safety requirements.

OBJECTS OF THE INVENTION SUMMARY OF THE INVENTION According to the invention these objects will be achieved by disposing the impact switch in the area of (adjacent to) a primer-oscillating slide and its driving unit and by providing a mechanical -lock for the impact switch. The switch is operated by the primer-oscillating slide and is released by the primer-oscillating slide only in the primed position of the slide..

Preferably, the impact switch is disposed with its axis parallel to that of the primer oscillating slide and is provided with an extension reaching behind the primer oscillating slide. The primer-oscillating slide is provided with an axial recess, which aligns with'and releases the extension of the impact switch in'the primed position of the primer oscillating slide.

This arrangement according to theinvention makes it possible to produce the detonating system in compact design, so that it can be inserted as a whole into the detonator housing. In the case of the detonator according I to the invention it is possible in a simple. manner to test this detonator unit in regard to-its functions during and after its assemblage outside the detonator housing or when inserted in the lower part of it. Moreover, it is possible as a result of the locking mechanism provided,

to prevent any movement of the impact switch,- as long as the primer-oscilalting slide is not in its primedposition.

The invention is explained in detail in the following description on the basis of an embodiment shown by way of example in the drawing. 7 THE DRAWING FIG. -1 shows a plan view of the detonator according to the invention in the direction of arrow A in FIG. 3.

FIG. 2 is a plan view'of the detonator according to FIG. 1, whereby however the primer-oscillating slide is' in a primed position. j

FIG. 3 is a fragmentary elevation view with portions shown in section by a cut taken along line III-III in FIG. 1.

FIG. 4is a fragmentary elevation view with-portions shown in section by a cut taken along line IV -IV in Y F IG. 2. v

FIG. 5 is a view in perspective of a portion'ofthe detonator. FIG. 6 is a schematic elevational view of a portion of the detonator;

FIG. 7 is a fragmentaryview of the detonator and its detonating circuit.

DESCRIPTION OF A PREFERRED EMBODIMENT In the drawing (particularly FIG. 4), the numerals ll),

ll, 12 and 19'designate several plate slabs defining a unitary frame structure, in which the individual elements of the detonator are mounted. We are dealing here essentially with adetonatonas disclosed for example in the German published application No. 1,924,025, the disclosure of which'being-hereby incorporated by reference. A so-called clearing weight or setback mass 20 is mounted longitudinally shiftablyon a bolt, or pin, 21 and which is forced by-a spring 22 into the position shownin'FlG. 4; The detonator is installed in a projectile in such away thatthe bolt2l runs parallel to the longitudinal axis of the projectile, i.e., whereby the point of the projectile is'above the plate slab l9.

Upon discharge of the projectile, the clearing we'ight '20 is moved rearwardly, by the relative acceleration,-

counter to the'action of-springZZ. Asa result, the fuze safety cap 23 is moved via a known'ele'ment 50. The el- Y ement 50 comprises a lever having a first arm section 50a arrangedto bejengaged by the setbackmass 20' and a second arm section 505 arranged to extend within a slot 23b in the safety cap 23 (see FIGS. 5 and'6). The lever element 50 is mountedona pivot pin-"52 intermediate the sections 50a and 50b and is spring biased toward the setback mass 20 such that'the'firstarm por- 'tion 50a, lies against the setbackmass 20 below a conical portion of the setback mass 20. Upon discharge of the projectile, the setback mass 20 overcomes the force of its spring 22 and shifts rearwardly on the pin 21. In so doing, the conical part of the setback mass cams the first arm section 50a outwardly, thereby rotating the lever 50. Such rotation of the lever is transmitted to the safety cap 23 through the arm section 50b to rotate the safety cap, so that the supporting fingers 28a on the finger disk 28 can engage with the slits 23a of the fuze safety cap 23. The finger disk 28 is connected with the inertia weight 25 such that after the fingers 28 are disposed above and aligned with the slits 23a, the inertia weight 25 can be moved linearly rearwardly, by relative acceleration, counter to the force of the spring 27.

The inertia weight 25 encircles and is slidably mounted on a shaft 24, which shaft has a helical or screw-shaped groove 54 on its circumference (FIG. 6). A finger 56 of the inertia weight 25 engages this groove. As a result of the movement of the inertia weight 25 along the shaft 24, the shaft 24 will be rotated by the finger. This rotation of the shaft 24 is transmitted to gear assemblies 38 and 39 via a gear 26 connected firmly with the shaft 24. The gear 39 is in effective connection with an oscillating annature 40. In this way the rotation of shaft 24 is checked. This oscillating armature may comprise a known type of escapement device.

The numeral 30 designates the primer-oscillating slide, which contains the primer capsule 31. The capsule 31 is provided with a known electric detonator element 60. This detonator element is electrically connected on the one hand with the oscillating slide 30 via line 62 and, by way of the shaft 32, with the plate slabs. It is connected on the other hand with a contact 36 attached to a lamella in an insulated manner via line 64. The line 64 may be embedded within a plate 34 or within an external coating on the plate so as to be insulated from the plate slabs, as will be apparent to those skilled in the art. This contact is disposed in the perforation of a plate 34 which constitutes a movable arm connected with oscillating slide 30 (FIG. 1). The plate 34 is arranged for rotation within a slit 12a (of the plate 12a) about the shaft 32.

In the safety position of the detonator, the oscillating slide 30 (or its plate 34) is in the position shown in FIG. 1, disposed behind a slotted, hollow end 24a of the shaft 24, which shaft can be turned by the inertia weight 25. In this position a portion of the detonator circuit is open, i.e., no detonating signal may be sent to the detonator element. Upon discharge of the projectile, the inertia weight 25, as already stated, after its release moves counter to the force of the spring 27. As a result, the shaft 24 is rotated. After a turn of 180, the slot of the end 240 of the shaft 24 faces an offset part 34a of the plate 34 so that the offset part 340 can engage with, Le, enter, the inside of the hollow end 24a of the shaft 24.

After discharge of the projectile, whenever therefore. the acceleration has decreased to below a certain value, the inertia weight 25 is forced into its original position by the spring 27. As a result, the shaft 24 is now turned in the reverse direction, until the lateral slot in the hollow end 24a of the shaft is again in the position shown in FIG. 1. Now the offset part 340 of the plate 34 can emerge from the hollow end 24a of the shaft and can move further in the slit 12a of the plate slab part 12a. This shifting movement is caused by a helical spring 33, which engages at one end with the plate slab 12 and at the other end with the oscillating slide 30.

Whenever the plate 34, connected firmly with the oscillating slide 30, reaches its terminal position (FIG. 2), then the contact 36 is connected electrically with the counter contact 37 in the plate slab 12. In this position the detonator element is connected to the detonator circuit. The detonator is fired as soon as the impact switch 15, 16, and 17 is closed.

This impact switch consists of two resilient contact lamellae l6 and 17, which are disposed on a plate 18. This plate can be provided with a printed circuit, for example. One of the contacts 16 and 17 is connected with a voltage source via line 72, for example, while the other contact is connected electrically with contact 37 via line 66. The voltage source 70 is suitably grounded to the plate slabs. The electric connection between the contacts 16 and 17 is established by a metal ring 15 which is placed on an insulating sleeve 14. The insulating sleeve 14 is disposed on one end 13a of a bolt or pin 13. This bolt 13 carries a collar 13b, which abuts and supports a spring 41. The spring 41, in turn, attempts to force the bolt 13 into the position shown in FIG. 3, in which the portion of the detonator circuit defined by the impact switch 15-17 is opened.

The bolt 13 is extended beyond the collar 13b. It lies essentially parallel to the axis of the shaft 32 of the oscillating slide 30. The bolt 13 has an enlargement or collar 13c at its other end, which in the safety position of the oscillating slide 30, extends behind a locking extension on the plate 34 of the oscillating slide (FIG. 3). The impact switch is thus locked in this position of the oscillating slide and the impact switch 15-17 cannot be closed.

The oscillating slide 30, as can be seen from FIGS. 1, 2 and 3 is provided with an axis-parallel recess 300, into which the collar of the bolt 13 can drop, whenever the oscillating slide 30 is in its primed position (FIG. 2). If now the projectile hits a target, then the bolt 13 is moved forward by the delay counter to the force of the spring 41 and thus the impact switch and the detonator circuit are closed (FIG. 4).

Naturally the measures according to the invention can also be used with detonators where the safety chain is constructed differently, from the one described previously. For example, in the case of use of a safety chain which responds to rotation, the plate 34 with its offset element 34a can be omitted. The primeroscillating slide 30 can then be released directly by a centrifugal weight into the cocked position.

MAJOR ADVANTAGES AND SCOPE OF THE INVENTION The compact arrangement of the various elements of the present invention provides a detonator system which may be conveniently inserted as a unit within a detonator housing. Moreover, the system may thereafter be conveniently tested.

Additionally, the impact switch is effectively locked in its circuit-open position until the remainder of the circuit is closed, thereby preventing premature detonation.

Although the invention has been described in connection with a preferred embodiment thereof, it will be appreciated by those skilled in the art that additions, modifications, substitutions and deletions not specifically described may be made without departing from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. In an electric detonator assembly for a projectile, said assembly comprising a primer means; electrically actuable primer-detonating means; a detonator circuit connectable between a power source and said primerdetonating means; an impact-responsive switch having a movable element for closing a first portion of said detonator circuit, said impact switch element being normally disposed in a circuit-open position and being mounted so as to be urged toward a circuit-closing position in response to impact of said projectile after launching; a movable arm, said arm having means for closing a second portion of said detonator circuit; means for urging said arm from a safety position in which said second circuit portion is open toward a priming position in which said second circuit portion is closed; safety means for restraining movement of said arm toward its priming position prior to launching of the projectile and for releasing said arm for movement toward its priming position subsequent to launching of the projectile; the improvement wherein:

said impact switch element is disposed adjacent said arm; and

mechanical locking means being operably connected to said arm and being shiftable in response to movement of said arm for:

retaining said impact switch element in its circuitopen position when said arm is disposed in its safety position, and

releasing said impact switch element when said arm is disposed in its priming position such that said impact switch element is capable of movement to a circuit-closing position in response to impact of the launched projectile.

2. The apparatus of claim 1 wherein said movable arm carries said primer means and is mounted for rotation; said impact switch element being disposed with its axis parallel to the rotary axis of said movable arm, saidmechanical locking means comprising a portion of said movable arm, said impact switch element including an enlargement extending past and abutting said portion of said movable arm, said movable arm including a recess which. in the priming position of said movable arm, aligns with said enlargement to release said impact switch element for longitudinal movement.

3. Apparatus according to claim 2 wherein said safety means includes means responsive to deceleration of the launched projectile for releasing said arm for movement.

4. An electric detonator assembly insertable as a unit within a detonator housing and comprising:

a plurality of rigid plate members defining a unitary frame structure;

a primer-oscillating slide including a plate mounted on said unitary frame structure for rotation about an axis; said plate carrying a primer capsule and electric detonating equipment;

a detonator circuit for connecting the detonating equipment with a source of power; said plate carrying a contact and being rotatable from a safety position wherein one portion of the detonating circuit is open, and a primed position in which this one portion of the circuit is closed;

at one end and being shiftably movable along its longitudinal axis between a circuit-open position wherein said conducting means is disconnected from another portion of said detonator circuit, and a circuit-closed position wherein said conducting means is connected to and closes said other portion of the detonator circuit; said pin being disposed adjacent said plate and extending in a direction parallel to the rotary axis of said plate; spring means for biasing said pin toward its circuitopen position; said plate, in its safety position, having locking means abutting against an enlarged portion of said pin to restrain said pin from longitudinal movement toward its circuit-closed position; said plate, in its primed position, having recess means aligned with the enlarged portion of the pin to permit movement of the pin toward its circuit-closed position; said pin being responsive to impact of the projectile to shift longitudinally toward its circuit-closed position, when said plate is disposed in its primed position, to close said detonator circuit. 

1. In an electric detonator assembly for a projectile, said assembly comprising a primer means; electrically actuable primerdetonating means; a detonator circuit connectable between a power source and said primer-detonating means; an impact-responsive switch having a movable element for closing a first portion of said detonator circuit, said impact switch element being normally disposed in a circuit-open position and being mounted so as to be urged toward a circuit-closing position in response to impact of said projectile after launching; a movable arm, said arm having means for closing a second portion of said detonator circuit; means for urging said arm from a safety position in which said second circuit portion is open toward a priming position in which said second circuit portion is closed; safety means for restraining movement of said arm toward its priming position prior to launching of the projectile and for releasing said arm for movement toward its priming position subsequent to launching of the projectile; the improvement wherein: said impact switch element is disposed adjacent said arm; and mechanical locking means being opErably connected to said arm and being shiftable in response to movement of said arm for: retaining said impact switch element in its circuit-open position when said arm is disposed in its safety position, and releasing said impact switch element when said arm is disposed in its priming position such that said impact switch element is capable of movement to a circuit-closing position in response to impact of the launched projectile.
 2. The apparatus of claim 1 wherein said movable arm carries said primer means and is mounted for rotation; said impact switch element being disposed with its axis parallel to the rotary axis of said movable arm, said mechanical locking means comprising a portion of said movable arm, said impact switch element including an enlargement extending past and abutting said portion of said movable arm, said movable arm including a recess which, in the priming position of said movable arm, aligns with said enlargement to release said impact switch element for longitudinal movement.
 3. Apparatus according to claim 2 wherein said safety means includes means responsive to deceleration of the launched projectile for releasing said arm for movement.
 4. An electric detonator assembly insertable as a unit within a detonator housing and comprising: a plurality of rigid plate members defining a unitary frame structure; a primer-oscillating slide including a plate mounted on said unitary frame structure for rotation about an axis; said plate carrying a primer capsule and electric detonating equipment; a detonator circuit for connecting the detonating equipment with a source of power; said plate carrying a contact and being rotatable from a safety position wherein one portion of the detonating circuit is open, and a primed position in which this one portion of the circuit is closed; spring means for biasing said plate to its primed position; means on said unitary frame structure for retaining said plate in the safety position thereof and being responsive to the firing of the associated projectile to release said plate for movement toward its primed position to close said one portion of the detonator circuit; inertia switch means mounted on said unitary frame structure including a pin having conducting means at one end and being shiftably movable along its longitudinal axis between a circuit-open position wherein said conducting means is disconnected from another portion of said detonator circuit, and a circuit-closed position wherein said conducting means is connected to and closes said other portion of the detonator circuit; said pin being disposed adjacent said plate and extending in a direction parallel to the rotary axis of said plate; spring means for biasing said pin toward its circuit-open position; said plate, in its safety position, having locking means abutting against an enlarged portion of said pin to restrain said pin from longitudinal movement toward its circuit-closed position; said plate, in its primed position, having recess means aligned with the enlarged portion of the pin to permit movement of the pin toward its circuit-closed position; said pin being responsive to impact of the projectile to shift longitudinally toward its circuit-closed position, when said plate is disposed in its primed position, to close said detonator circuit. 